In article <mailman.736.1372773195.20661.bind-us...@lists.isc.org>, Steven Carr <sjc...@gmail.com> wrote:
> On 2 July 2013 14:42, Sam Wilson <sam.wil...@ed.ac.uk> wrote: > > Can anyone here give examples of the types of various software that will > > not operate without a PTR record? > > There have already been numerous listings of software that require > reverse lookups. SMTP being the main one. Other services like IRC and > some databases (Oracle/MySQL) can also be configured to require > properly working reverse lookups. "... can also be configured ..." - see below. > > I agree that if PTR records exist then they should match an A record. > > My experience (and IIRC correctly the word of several RFCs) is that PTRs > > are not required for most things to work. > > RFC1912 [http://tools.ietf.org/html/rfc1912] section 2.1... > > Every Internet-reachable host should have a name... Make sure your PTR > and A records match. For every IP address, there should be a matching > PTR record in the in-addr.arpa domain. If a host is multi-homed, > (more than one IP address) make sure that all IP addresses have a > corresponding PTR record (not just the first one). Failure to have > matching PTR and A records can cause loss of Internet services similar > to not being registered in the DNS at all. Also, PTR records must > point back to a valid A record, not a alias defined by a CNAME. Sorry for the delay in returning to this. RFC 1912 says: Status of this Memo This memo provides information for the Internet community. This memo does not specify an Internet standard of any kind. ... To make myself clear, I'm a big fan of correct PTR records and we try to make sure that our reverse DNS is fully populated. I do not regard lack of a valid PTR record to be a reason to refuse connection except, perhaps, in very particular circumstances, for instance where it might be part of a trust stance. That would be by agreement between consenting adults, not the law of Internetland in general. Sam -- The University of Edinburgh is a charitable body, registered in Scotland, with registration number SC005336. _______________________________________________ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
